Hi,
I feel like you really need to add more information about the Powershell task.
Personally, I'm having trouble figuring out how to run a Powershell script correctly, the behavior of the Powershell Task varies alot, especially when I'm importing modules in the script, such as AD module, Exchange etc.
I usually end up with just execute task, where i add:
C:\Windows\System32\WindowsPowerShell\v1.0\Powershell.exe -ExecutionPolicy Bypass -File "C:\SCRIPT.ps1"
Using the normal Powershell Task will usually give me a lot of crazy errors.
Windows Server 2008R2 x64, VisualCron 7.2.1, Powershell Version 3.0.